xenfb: Revert mm_lock changes. They're not needed.

Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com>

diff --git a/drivers/xen/fbfront/xenfb.c b/drivers/xen/fbfront/xenfb.c
index 53b080fc14126e461e1575ec9c9b48ad9fb49840..a98712768dfdacfac30510dc338e76b330ef028c 100644 (file)
--- a/drivers/xen/fbfront/xenfb.c
+++ b/drivers/xen/fbfront/xenfb.c
@@ -210,6 +210,8 @@ static void xenfb_update_screen(struct xenfb_info *info)
        if (xenfb_queue_full(info))
                return;
 
+       mutex_lock(&info->mm_lock);
+       
        spin_lock_irqsave(&info->dirty_lock, flags);
        if (info->dirty){
                info->dirty = 0;
@@ -221,12 +223,11 @@ static void xenfb_update_screen(struct xenfb_info *info)
                info->x2 = info->y2 = 0;
        } else {
                spin_unlock_irqrestore(&info->dirty_lock, flags);
+               mutex_unlock(&info->mm_lock);
                return;
        }
        spin_unlock_irqrestore(&info->dirty_lock, flags);
 
-       mutex_lock(&info->mm_lock);
-       
        list_for_each_entry(map, &info->mappings, link) {
                if (!map->faults)
                        continue;